(818.) NEW SPECIES OF FISHES. 227 



SliCOND ORDER OF FISHES, STURTONIENS, OR 

 CHONDROP TERIGIEIS S. 



With free Branchi^, 



These have gills much cloven, an operculum, but no 

 jays to the membrane. 



The second genus of this o»der, with free branchiae^", 

 contains but one species^ the Polyodon feuill , Squahis 

 spathula, of Lacepede, tom. i. p. 403. pi. xii. fig. 3. 

 which was from the Mississippi. An individual from 

 the river Ohio, was presented, by Mr. Hazard, to the 

 Academy, and this, in the form of its body^ fins and 

 snout, is closely allied to the foliated Polyodon, but 

 differs i!i the total absence of teeth. A circumstance 

 so remarkable authorizes us to consider the present in- 

 dividual a new species, and perhaps the type of a new 

 subgenus near Polyodon. Both species, however, so 

 much alike in body, fins and snout, might well be uni- 

 ted under the name Spatidaria^ Schn. if we reject the 

 teeth from those characters attached to the genus by 

 Cuv er and Lacepede In other respects they resemble 

 each other. The two then would be specifically distin- 

 guished, one with teeth, the other without teeth. Or, 

 should the adoption of a new genus be preferred, I would 

 propose the following characters. 



Genus PLAITROSTRA. 

 Gen. char, Jaiv^ tongue and throat destitute of teeth. 

 Snout flattened, elongated and spathuliform. Fins and 

 hodif closely resembling those of the Sturgeon, but with- 

 out plates. The tail only is covered on each side by small 

 bo.ny plates, as in that genus. 



* Cuvier, Regne Animal. 



